Plano Concave Lens – Precision Negative Lenses for Diverging Light Applications

What is a Plano Concave Lens?

A plano concave lens is a type of negative lens featuring one flat (plano) surface and one inward-curved (concave) surface. It diverges incoming light rays and is widely used in beam expansion, vision correction devices, and laser collimators.

At Bote Optics Singapore, we specialize in custom plano concave lenses crafted with premium materials and precise coatings for various industrial and scientific uses.

Plano Concave Lens Definition – Simplified

A plano concave lens is an optical lens with:

• One flat surface (plano)
• One inward-curved surface (concave)

This design causes parallel rays of light to diverge after passing through the lens. These lenses form virtual, upright, and diminished images.

Key Specifications – Bote Plano Concave Lenses

🔧 Need plano concave lenses with DLC or BBAR coatings? Contact us

Plano Concave Lens Ray Diagram

A typical ray diagram for a plano concave lens:

• Parallel incident rays diverge after passing through the lens.
• The diverged rays appear to originate from a virtual focal point located on the incident side.

Image: Ray tracing in a plano concave lens showing divergence of rays

Plano Concave Lens Formula & Focal Length

1. Lensmaker’s Equation for Plano Concave Lens:

1f=(n−1)(1R1−1R2)\frac{1}{f} = (n – 1)\left(\frac{1}{R_1} – \frac{1}{R_2}\right)f1​=(n−1)(R1​1​−R2​1​)

For a plano concave lens:

• R1=∞R_1 = \inftyR1​=∞ (flat surface)
• R2=−RR_2 = -RR2​=−R (concave surface)

So, 1f=(n−1)(0−1R)=−(n−1)R\frac{1}{f} = (n – 1)\left(0 – \frac{1}{R}\right) = -\frac{(n – 1)}{R}f1​=(n−1)(0−R1​)=−R(n−1)​

Where:

• fff = Focal length (negative)
• nnn = Refractive index of lens material
• RRR = Radius of curvature of the concave surface

2. Plano Concave Lens Radius of Curvature

If you know the focal length and refractive index: R=−(n−1)fR = -(n – 1)fR=−(n−1)f

What Are Plano Lenses?

Plano lenses have at least one flat surface. They are used in various lens types:

• Plano-Convex: For focusing light
• Plano-Concave: For diverging light
• Plano-Concave Cylindrical: For line focusing or spreading

Plano Concave Lens Uses

💡 Our plano concave lenses are often paired with plano convex lenses in beam shaping assemblies.

Plano Concave Lens Diagram – Physical Structure

Image: Structural representation of a plano concave lens

• Left surface: Plano (flat)
• Right surface: Concave
• Light enters from the plano side and diverges after exiting

In the Given Figure – A Plano Concave Lens…

You may find this type of lens in physics problems involving:

• Virtual image formation
• Negative focal length
• Diverging ray paths traced backward to a focal point

Plano Concave Lens Physics Applications

• Demonstrates negative focal length in lens physics labs
• Helps explain virtual image concepts in geometric optics
• Ideal in experiments on refraction and divergence

FAQs – Plano Concave Lenses

Q1: What is the focal length of a plano concave lens?
A: The focal length is always negative, indicating the lens is diverging.

Q2: How does it differ from a biconcave lens?
A: Biconcave lenses have two concave surfaces, providing stronger divergence. Plano concave lenses are often preferred when space constraints exist or when minimal distortion is needed.

Q3: Can I order plano concave lenses with AR coatings?
A: Yes, Bote Optics offers AR coatings tailored to UV, visible, NIR, and IR ranges.

Q4: What materials are suitable for plano concave lenses?
A: BK7 for visible light, Fused Silica for UV, and ZnSe or Ge for IR.

Q5: How do you determine the radius of curvature?
A: Using the formula R=−(n−1)fR = -(n – 1)fR=−(n−1)f, based on desired focal length and material index.

Plano Concave Lens Price Range

📦 Need export-ready plano concave lenses with ITAR-free supply? We ship globally from Singapore.

Why Choose Bote for Plano Concave Lenses?

• 🏭 In-house Manufacturing in Nanjing
• 🧪 Precision Testing & Coating in Singapore
• 🛠️ Custom Curvature and Optical Coating Options
• 🌐 Fast Prototyping & Global Export Support

Whether you need single-wavelength AR coatings or plano lenses for high-power laser systems, our team is ready to support your project.

Internal Links to Related Products

• Plano Convex Lenses
• Biconcave Lenses
• Custom Optical Components
• Get a Quote

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🌐 Visit: www.bote.com.sg

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